1. Field of the Invention
The invention relates to surface cleaning. In one aspect, the invention relates to a vacuum cleaner having a system for removing soiled spots from carpets with chemicals. In another of its aspects, the invention relates to a dry vacuum cleaner with a system for delivering a powdered cleaning solution to a surface to be cleaned for cleaning soiled spots on a carpet and removing the powdered cleaning solution along with the soil from the carpet surface. In another aspect, the invention relates to a vacuum cleaner for delivering a liquid cleaning solution and a powdered cleaning solution in succession and removing the cleaning solutions from the surface to be cleaned. In another of its aspects, the invention relates to a method for cleaning a surface that has soiled areas with vacuum, cleaning powder and a cleaning liquid.
2. Description of the Related Arts
Floor coverings such as carpets and rugs are prone to marks and stains. Floor coverings can be cleaned in a number of ways, which can be classified as ‘wet’ or ‘dry’ cleaning methods. Wet cleaning methods such as washing or shampooing the floor covering have the disadvantage that they leave behind significant residual moisture in the surface to be cleaned, which renders the surface unusable until sufficiently dry. Wet cleaning methods may also cause shrinkage of the floor covering. Dry cleaning generally involves depositing a powdered composition onto the floor covering which can readily absorb soil and contaminants from the floor covering. The powder is worked into the floor covering with the aid of a brush. Finally, the dirty powder can then be removed from the floor covering by a vacuum cleaner. While such compositions are called ‘dry’, in that they flow as a powder at room temperature, they usually contain a quantity of liquid such as water or organic solvents.
Dry vacuums are known devices for cleaning carpets and other fabric surfaces, such as rugs and upholstery. Some dry carpet vacuums comprise a powder delivery system and a recovery system. The powder delivery system typically includes one or more powder supply containers for storing a supply of cleaning powder and a powder distributor for applying the cleaning power to the surface to be cleaned. The recovery system typically comprises a recovery tank, a nozzle adjacent the surface to be cleaned and in fluid communication with the recovery tank through a working air conduit, and a suction source. The suction source is typically in fluid communication with the working air conduit to draw the soiled cleaning powder from the surface to be cleaned through the nozzle and the working air conduit to the recovery tank.
U.S. Pat. No. 4,245,371 to Satterfield discloses a carpet cleaning machine that can dispense a damp cleaning compound from a powder chamber using a reticulated foam cylinder. A lever is provided for controlling the operation of the foam cylinder. When the powder is being deposited on the surface, a vent is open to the atmosphere so that the vacuum fan will not suck up the powder before the brushes accomplish their cleaning function. When it is desired to vacuum the surface, the lever is moved to the down position to deactivate the powder foam cylinder, which closes the vent allowing the vacuum fan to suck the dispensed powder and accumulated soil into the collection bag of the vacuum chamber.
U.S. Pat. No. 4,447,930 to Glenn et al. discloses a vacuum cleaner having a powder dispenser for storing and selectively dispensing a powder. The dispenser includes a retaining chamber having a dispensing roll and agitating rod for breaking up clumps of powder and facilitating dispensing of the powder through slots. A sliding door can be moved by a lever to block the slots by means of a user actuated slide switch in the control handle. The vacuum can be selectively operated through a push button in a clean mode in which suction is turned off while the powder is dispensed and worked into the carpet by the brush.
U.S. Pat. No. 6,993,807 to Courtney discloses a vacuum cleaner having a dispenser for dispensing dry cleaning material onto a floor surface. The dispenser mounts to an upper face of the cleaner head. The dispenser is connected with a foot pedal that a user can press to rotate the dispenser from an inoperable, upright position to an operable position in which the dispenser is flush with the cleaner head. The dispenser comprises a hopper housing having a plate. The plate has an arm that is movably mounted to a cam that is driven by the main motor of the cleaner. Movement of the plate causes a wire carried by the plate near the dispensing aperture to vibrate to separate powder clumps prior to dispensing. The vibration of the plate also causes the powder to move downwards towards the dispensing aperture.